Clinical Outcomes of Mitral Valve Surgery in Atrial Functional Mitral Regurgitation in the REVEAL-AFMR Registry

This cohort study, called the Real-World Observational Study for Investigating the Prevalence and Therapeutic Options for Atrial Functional Mitral Regurgitation (REVEAL-AFMR), aimed to investigate the prevalence, clinical characteristics, and outcomes of mitral valve (MV) surgery in atrial functional mitral regurgitation (AFMR). The study was conducted across 26 Japanese centers, reviewing all transthoracic echocardiograms performed between January and December 2019 to enroll adult patients with moderate or severe AFMR. Patients who underwent MV surgery, with or without tricuspid valve surgery, were compared to those who did not undergo surgery. The primary outcome was a composite of heart failure hospitalization and all-cause mortality.  Among 177,235 patients who underwent echocardiography, a total of 8,867 had moderate or severe MR. Within this group, 1,007 (11.4 percent) were diagnosed with AFMR (mean [SD] age, 77.8 [9.5] years; 55.7 percent female), and 807 (80.1 percent) had atrial fibrillation. Of these patients, 113 underwent MV surgery, with 92 (81.4 percent) receiving concurrent tricuspid valve surgery. Despite a more severe disease status, only the surgical group showed a decrease in natriuretic peptide levels at follow-up and had a significantly lower rate of the primary outcome (three-year event rates were 18.3 percent versus 33.3 percent; log-rank P = .03). Statistical adjustments did not alter these findings. The authors conclude that in patients with AFMR, MV surgery was associated with lower rates of adverse clinical outcomes.